In current information era, human beings by degrees tend to rely on electronic products. The electronic products such as mobile phones, handheld personal computers (PCs), personal digital assistants (PDAs) and smart phones have pervaded everywhere in our daily life. To meet current demands on portable, compact, and user-friendly information technology (IT) products, touch panels have been introduced as input devices in replacement of conventional keyboards or mice.
A touch panel (or a touch screen) is widely used in electronic devices to detect an input action or an event by a user. Typically, the touch panel may detect the presence and location of a touch of the user by generating an electrical signal when the touch panel is touched by a finger, a stylus pen, or the like. The touch panel is usually mounted on a display panel, e.g., an organic light-emitting diode (OLED) display panel, a liquid crystal display (LCD) panel, etc., or may be formed within the display panel. The touch panel may be classified into, e.g., a resistive touch panel, a capacitive touch panel, an electromagnetic touch panel, an infrared touch panel, a surface acoustic wave (SAW) touch panel, a near field imaging (NFI) touch panel, etc. Among the touch panels, a touch display panel capable of performing both a touch function and a display function is one of the most popular products at present.